FSCTL_SET_REFS_SMR_VOLUME_GC_PARAMETERS control code

The FSCTL_SET_REFS_SMR_VOLUME_GC_PARAMETERS control code controls the garbage collection on a Shingled Magnetic Recording (SMR) volume.

BOOL
   DeviceIoControl( (HANDLE)       hDevice,         // handle to volume
                    FSCTL_SET_REFS_SMR_VOLUME_GC_PARAMETERS, // dwIoControlCode
                    (LPDWORD)      lpInBuffer,      // input buffer
                    (DWORD)        nInBufferSize,   // size of input buffer
                     NULL,     // output buffer
                     0,  // size of output buffer
                    (LPDWORD)      lpBytesReturned, // number of bytes returned
                    (LPOVERLAPPED) lpOverlapped );  // OVERLAPPED structure

Parameters

• hDevice [in]: A handle to the device. To obtain a device handle, call the CreateFile function.

• dwIoControlCode [in]: The control code for the operation. Use FSCTL_SET_REFS_SMR_VOLUME_GC_PARAMETERS for this operation.

• lpInBuffer [in]: A pointer to a caller-allocated REFS_SMR_VOLUME_GC_PARAMETERS structure.

• nInBufferSize [in]: The size of the input buffer, in bytes.

• lpOutBuffer [out]: Not used with this operation; set to NULL.

• nOutBufferSize [in]: Not used with this operation; set to zero.

• lpBytesReturned [out]: Not used with this operation; set to NULL.

• lpOverlapped [in]: A pointer to an OVERLAPPED structure.

  If hDevice was opened without specifying FILE_FLAG_OVERLAPPED, lpOverlapped is ignored.

  If hDevice was opened with the FILE_FLAG_OVERLAPPED flag, the operation is performed as an overlapped (asynchronous) operation. In this case, lpOverlapped must point to a valid OVERLAPPED structure that contains a handle to an event object. Otherwise, the function fails in unpredictable ways.

  For overlapped operations, DeviceIoControl returns immediately, and the event object is signaled when the operation has been completed. Otherwise, the function does not return until the operation has been completed or an error occurs.

Return value

If the operation completes successfully, DeviceIoControl returns a nonzero value.

If the operation fails or is pending, DeviceIoControl returns zero. To get extended error information, call GetLastError.

Requirements

See also

DeviceIoControl